implmex
Diamond
- Joined
- Jun 23, 2002
- Location
- Vancouver BC Canada
Good morning All:
I got an RFQ recently for an aluminum turned shaft about 7" long and about 0.1" diameter at the skinniest point (right in the middle of the length).
There are some conical features on the shaft and the engineer is specifying a 0.1 micron RA finish on those surfaces in order to bounce a laser off them onto a target.
I assume but do not know whether the shaft rotates during function.
The finish callout strikes me as extraordinarily ambitious given the material, the likelihood that the shaft will move all over the place from stress release, and the inability of the engineer to specify just how they intend to determine that I've actually achieved the finish they've called out.
When I remarked that this finish means you don't get to wipe off the dirty fingerprints with toilet paper without fucking it up, I got a dead silence at the other end of the phone.
When I pointed out that if there are geometric inconsistencies in the features, the laser will bounce to an unintended location and may not hit the detector, I got another dead silence.
BTW, there is no concentricity callout, and the overall dimensional tolerances quoted in the title bar are very generous (+/- 0.1 mm, and +/- 0.5 degree).
I smell a clusterfuck of monumental proportions coming my way if I accept the job and the part doesn't work.
They've come to me because others have wisely refused to bid on the part.
It sounds like I have carte blanche from the purchaser on this project if I agree to do it.
They sound desperate.
So what would you do?
I don't need the hassle of a failed part.
The customer has been good to me over the years.
The engineer is a young guy just out of university...bright kid but rather inexperienced.
My personal temptation is to let this one go and lose the customer, but I do like a challenge.
So I ask myself, (and you guys): is this a legitimate challenge or a fool's errand?
I eagerly await all opinions.
Cheers
Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
I got an RFQ recently for an aluminum turned shaft about 7" long and about 0.1" diameter at the skinniest point (right in the middle of the length).
There are some conical features on the shaft and the engineer is specifying a 0.1 micron RA finish on those surfaces in order to bounce a laser off them onto a target.
I assume but do not know whether the shaft rotates during function.
The finish callout strikes me as extraordinarily ambitious given the material, the likelihood that the shaft will move all over the place from stress release, and the inability of the engineer to specify just how they intend to determine that I've actually achieved the finish they've called out.
When I remarked that this finish means you don't get to wipe off the dirty fingerprints with toilet paper without fucking it up, I got a dead silence at the other end of the phone.
When I pointed out that if there are geometric inconsistencies in the features, the laser will bounce to an unintended location and may not hit the detector, I got another dead silence.
BTW, there is no concentricity callout, and the overall dimensional tolerances quoted in the title bar are very generous (+/- 0.1 mm, and +/- 0.5 degree).
I smell a clusterfuck of monumental proportions coming my way if I accept the job and the part doesn't work.
They've come to me because others have wisely refused to bid on the part.
It sounds like I have carte blanche from the purchaser on this project if I agree to do it.
They sound desperate.
So what would you do?
I don't need the hassle of a failed part.
The customer has been good to me over the years.
The engineer is a young guy just out of university...bright kid but rather inexperienced.
My personal temptation is to let this one go and lose the customer, but I do like a challenge.
So I ask myself, (and you guys): is this a legitimate challenge or a fool's errand?
I eagerly await all opinions.
Cheers
Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining